1. Field of the Invention
This invention relates generally to rotating heads used with rotary drilling rigs in well drilling, primarily oil and gas wells. The disclosed is an improved rotating head that is easier to use and maintain, can be used with smaller drilling rigs and that has dramatic improvement in the sealing capabilities of the bearing assembly, even under high pressure conditions.
Rotating heads are known in the art to be a sealing device used to control the direction of the drilling fluid cuttings as they return to the surface, and to close off the annular space around the kelly in drilling with pressure at the surface. Rotating heads are usually installed above the main blowout preventers and make it possible to drill ahead even when there is pressure in the annulus that the weight of the drilling fluid is not overcoming (preventing the well from blowing out). The rotating head helps insure the safety of the rig personnel, equipment and environment. It can also lower drilling costs and increase well productivity.
2. Description of Related Art
U.S. Pat. No. 7,870,896 issued Jan. 18, 2011 describes an improved rotating head that utilizes a box assembly and an integrated wear surface to seal the bearing elements. It describes the need for improved sealing, lubricating and cooling of bearings to maximize the useful life of the bearings. Part of the reason this is so important is because downtime of the drilling rig for maintenance is extremely costly for the operating companies, who need to keep the drilling rigs running almost non-stop.
U.S. Pat. No. 5,647,444 issued on Jul. 15, 1997 describes a stationary bowl designed to support a blowout preventor bearing assembly. It receives a swivel ball that cooperates with the bowl to self-align the blowout preventor bearing assembly and the swivel ball with respect to the fixed bowl.
U.S. Pat. No. 5,137,084 describes a rotating head having a bowl assembly and a rotating assembly disposed in a bowl opening formed in the bowl assembly where the rotating bushing bearingly contacts a portion of the bowl assembly during the operation of the rotating head and where the rotating assembly is removable from the bowl assembly and can be replaced with another rotating assembly thereby simultaneously replacing the elastomeric member and the rotating bushing.
With regard to known rotating heads, most are large, bulky, heavy and difficult to perform maintenance on. The bearing assembly typically extends vertically up from the bowl housing a good eight to eleven inches, making the entire device to tall and large to use with smaller drilling rigs.
Rotating heads typically have bearing assemblies that are not internally sealed, requiring the operators to continually run oil in the bearing assembly to keep the bearings lubricated and to prevent the bearings from seizing. The clamping system on most rotating heads is typically a one-piece buckle type mechanism that requires a great deal of space to open and a great deal of strength and force to close.
There is a need for an improved rotating head that is smaller, less bulky and easier to maneuver and work on in the field. There is a need for an improved rotating head that requires less maintenance and is easier to perform maintenance on when it is required. There is a need for an improved rotating head that has superior sealing capabilities to improve performance and lifespan. There is a need for an improved rotating head that reduces the down time associated with bearing assembly malfunctions. There is a need for a rotating head that can be used with smaller drilling rigs.